A vehicle's fuel economy can be improved by making it smaller and lighter and giving it a smaller engine. But many consumers want sports cars, SUVs and trucks—while desiring good gas mileage, too. In an effort to improve fuel economy without shrinking vehicles, automakers have been increasingly turning to aerodynamics. The more aerodynamic a vehicle, the better fuel economy it will realize.
One way to improve the aerodynamics of a vehicle is to partially cover the wheels, in essence by extending the vehicle body over the wheel well. However, wheel covers obstruct the view of the wheel and the wheel rims, having a negative impact on aesthetics. Because of this, many vehicle owners, and thus automakers, are not taking advantage of the aerodynamic improvement provided by wheel covers.